(1) Field of the Invention
The present invention relates to a recording/playback apparatus for recording and playing back data to/from a rewritable optical disc such as DVD-RAM, DVD-R, and DVD-RW.
(2) Description of the Related Art
Recording/playback apparatuses for rewritable optical discs can perform variable playback operations such as special playback and random access operations and can also perform variable editing operations such as virtual and real editing operations, by accessing discs conforming to the DVD-VIDEO RECORDING standard. Such recording/playback apparatuses have enormous values as commercial products. In such recording/playback apparatuses, the program for performing recording, playback, and editing presumes that the video data and management information recorded on the DVD has a data structure that conforms to the DVD-VIDEO RECORDING standard. The program fails to operate normally when trying to play back or edit data without a data structure that conforms to the DVD-VIDEO RECORDING standard.
When a DVD recording video data is inserted, a recording/playback apparatus performs an initial check to see whether the video data and management information recorded on the DVD conforms to the DVD-VIDEO RECORDING standard and whether the DVD has a portion that does not conform to the DVD-VIDEO RECORDING standard. The serious failures found through this inspection include: (1) destruction of the management information used for accessing the video data; (2) destruction of the management information related to playing back of the video data; (3) incorrect addresses of the video data or the management information; and (4) incorrect time codes of the video data. It is well known that such failures are caused by the dust or flaws on the disc surface. The general versatility of the DVD that the DVD can be accessed by even commercial personal computers is one of the main selling points of the DVD. Accordingly, a failure occurs when a personal computer writes data that violates the standard. There is another serious failure which is called a version confliction where the video data or the management information recorded on the disc conforms to a DVD-VIDEO RECORDING standard that is higher than the versions that the recording/playback apparatus can deal with. This failure can also interfere the normal operation of the recording/playback apparatus.
When a serious failure such as the destruction of the management information is found in the initial check of the inserted disc, conventional recording/playback apparatuses regard the DVD as an invalid disc. The recording/playback apparatus does not read nor write data from/to the “invalid disc”, without recognizing it as a medium. When this happens, the inserted DVD is treated in the same way as a recording medium that cannot be accessed by the recording/playback apparatus physically. Accordingly, to use the DVD, the user must initialize the DVD. With such initial check and recognition of discs with failures as invalid discs, it is possible to prevent the program loaded onto the recording/playback apparatus from hanging up. This increases the reliability of the recording/playback apparatus.
However, when light failures are treated in the same way as the serious failures, users would be required to initialize DVDs frequently.
On the contrary, when light failures are overlooked, users would worry that the playback/recording/editing program may start to operate abnormally at any moment.